BACKGROUND High-frequency chest wall oscillation (HFCWO) has been traditionally implemented for airway secretion clearance in conditions such as cystic fibrosis (CF) and bronchiectasis. There have been few reports of its use in refractory asthma. METHODS A 36-year-old, non-smoker male presented with a lifelong history of poorly controlled asthma. Despite multiple controller medications, he reported daily chest congestion, copious phlegm, and frequent exacerbations. Imaging, blood work, and bronchoscopy ruled out atypical infections, immunodeficiency, CF, and other chronic conditions. Pulmonary function tests supported a diagnosis of asthma. RESULTS We initiated HFCWO therapy twice daily in addition to standard inhaled pharmacological therapy. After 2 months, the patient noted resolution of respiratory symptoms as well as improvement in lung function. He remained symptom-free at his 2-year follow-up. CONCLUSIONS High-frequency chest oscillation may be useful in phenotypes of asthma characterized by prominent mucus hypersecretion.